For this tutorial I'm assuming Kubernetes with Helm + Ingress is already deployed. If not, I still included the commands I used near the end of this article.

OwnCloud

My NAS is running at home with Rockstor, and I'm using RAID10 with btrfs. Rockstor has (docker) apps support with the feature called Rock-on's, they also include OwnCloud, but after updating and some other issues with Rockstor at some point my deployment broke.
This frustrated me so I've decided to switch to Kubernetes instead.

I use my own cloud (no pun intended) as an alternative over using services owned by Google/Amazon/Apple.
When you plan to do the same, just make sure to also make proper backups.

Deploy OwnCloud with Helm

Following the instructions; copy their default values.yaml (from here). Tweak all the values. It seems important to define a hostname! (If you try accessing the service later via IP address, the webinterface will not accept this.)

Notes: owncloud.yaml is my values.yaml, and I expect the rbac.create=true not to be needed but I used it anyway it was left over when copy & pasting another command.. For convenience you can download my owncloud.yaml.

If you redeploy Kubernetes and/or the system in general, I forgot when exactly but a PersistentVolume may end up in a state that prevents PersistentVolumeClaim's to not bind to the Volumes.
There was a trick to force it to bind, IIRC kubectl edit pv kube-owncloud-storage-data and you can remove the reference it has to an existing PVC. But it was a few weeks ago I experimented with this so sorry I don't remember the details.
Only now I stumbled upon my notes and decided to wrap it up in a blog post.

They took me two hours of debugging, owncloud was throwing errors 413 Request Entity Too Large when syncing some larger video files from my phone to owncloud. Thinking this must be an issue inside owncloud I experimented with lots of parameters, fixes for php, apache, etc. Then realized it could be the Ingress in Kubernetes. The above example makes sure it doesn't block uploads up to half a gigabyte.